Determination of Skeletal Age

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Iliac Apophysis - Risser's Sign

In general the long bone growth plates close at 15 to 17 years in males and 13 to 15 years of age in females.

An accurate way to determine the skeletal age of a child is to use an X ray of the left wrist and to compare it with X rays in the Greulich and Pyle atlas. Here a series of X rays showing the development and ossification of the wrist, and hand bones is displayed, together with the average age these appear.

The axial skeleton matures a few years later than the limbs, and for scoliosis,the Risser sign is a useful method of bone age determination.

Skeletal age can be determined by the appearance of the iliac apophysis of the pelvis. The apophysis appears laterally on a pelvic X ray, and moves towards the spine as the patient approaches adulthood. Risser's sign is a measures the growth left in the spine - this may help to determine the potential for progression of scoliosis.

Risser's sign measures age from development of the growth plate of the Iliac apophysis

Grading (based on iliac crest divided into 4 quadrants)

    Risser's Sign
  • Risser 1: 25% iliac apophysis ossification Anterior Superior iliac spine (anterolateral) Seen in prepuberty or early puberty
  • Risser 2: 50% iliac apophysis ossification Ossification extends halfway across iliac wing Seen immediately before or during growth spurt
  • Risser 3: 75% iliac apophysis ossification. Indicates slowing of growth
  • Risser 4: 100% ossification, with no fusion to iliac crest . Indicates slowing of growth
  • Risser 5: Iliac apophysis fuses to iliac crest. Indicates cessation of growth.
A 'Risser 0' (before Risser 1) and Risser 5 are simlar in that both show no ossification centres on X ray. The two can be destinguished by age - an adolescent with Risser 5 grading will show no open growth plates in the long bones, and older be than 16 (female) or 18 (male), while a child with a Risser 0 grading will still have open growth plates in most of the long bones.

Risser Age Risser Age
1 13.8 1 15.2
2 14.3 2 15.2
3 14.7 3 16.3
4 16.0 4 16.3
5 16.1 5 18.0

Age determination in other areas

Other age determination systems are of value to the criminologist and immigration officials. It is sometimes crucial to determine if the individual is over 18 or 21, or at whatever age defines adulthood, and its attendant less lenient judicial treatment.

The third molar roots appear on X rays at age 18 years. The ossification of the sternal clavicular cartilage also occurs at age 18 years.



1.Greulich WW, Pyle SI: Radiographic Atlas of Skeletal Development of the Hand and Wrist, 2nd edition. Stanford, . CA: Stanford University Press, 1959.